18322440 has 64 divisors (see below), whose sum is σ = 55339200. Its totient is φ = 4852992.

The previous prime is 18322411. The next prime is 18322453. The reversal of 18322440 is 4422381.

18322440 = T₃₆₀ + T₃₆₁ + ... + T₅₃₈.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 18322440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21054 + ... + 21906.

It is an arithmetic number, because the mean of its divisors is an integer number (864675).

Almost surely, 2^18322440 is an apocalyptic number.

18322440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18322440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27669600).

18322440 is an abundant number, since it is smaller than the sum of its proper divisors (37016760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18322440 is a wasteful number, since it uses less digits than its factorization.

18322440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046 (or 1042 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 18322440 is about 4280.4719365976. The cubic root of 18322440 is about 263.6297610857.

The spelling of 18322440 in words is "eighteen million, three hundred twenty-two thousand, four hundred forty".